Afternoon all.
I've got a 99 runner, and lately when I start it up in the morning I notice that there is a odd, intermitent vibration when at idle. The engine will idle fine for one second, and then I'll notice a faint vibration for another. Then it will be fine, and then it will shudder again.
The idle speed seems fine since it will rev high initially, and then drop down as the engine warms. It idles at a steady 750 or so once it's totally warm. During the vibration, there's no increase in idle speed or anything.

has anyone else experienced a similar problem?

thanks!

Kevin

 

manual or auto tranny? If auto is it in neutral or in drive with foot on the break? If manual is it in 1st with clutch pedal pressed in or in neutral?

 

Sorry. I should have been more clear.
It's and auto.
And it's still in park while it's idling in my driveway.

 

I have the same problem on my 03 V6. Don't know what it is but after driving some other 4runners, I've noted that some do it and some don't.

I've read that the cause could be fan-belt-driven accessory, fly wheel, torque converter, tranny fluid pump, exhaust, motor mount, internal engine imbalance, etc.

I hope someone figures it out. Very annoying.